Laundry detergents are available in several different product formats like powders, granulates, liquids, gels or unit dose items such as tablets or pouches. Unit dose items particularly comply with the consumers' desires for simplified dosage. But, laundry tablets and pouches exhibit a few drawbacks. For example, tablets experience a delay in their dissolution in water due to their high densification and thus, a delay in their release of the important ingredients. In order to improve dissolution rates without being detrimental to tablet strength, several technical solutions have been found such as the use of disintegration aids. However, tables with disintegration aids are complex and have relatively high manufacturing costs since disintegration aids usually do not show further cleaning or conditioning properties.
The disadvantage of pouches that include liquid detergent is that incompatible ingredients cannot be formulated in one detergent. Additionally, a conventional wrapping material such as polyvinyl alcohol may not dissolute completely during the washing process and residues can be found on the fabrics.
Another alternative unit dose item is a water-insoluble substrate that is coated with laundry detergent. The laundry article is added together with the laundry to the washing machine. During the washing process the coating dissolves and thereby releases its ingredients to the wash liquor.
WO 07/1 20867 A2 discloses a laundry article that functions as a single product for washing and conditioning fabrics when added to the washing machine and then carried along with the wet clothes into the clothes dryer. The laundry article comprises a water-insoluble substrate onto which a minimum of two compositions is applied in “zones.” The water-insoluble substrate for the laundry article of the present invention is coated with a detergent composition and a fabric conditioning composition. In order to manufacture such a laundry article preferably a heated molten mixture of the particular compositions is coated onto the water-insoluble substrate.
Proteins, fats and starch often form constituents of persistent stains. In order to improve removal of such stains enzymes are commonly used in laundry detergents.
Especially due to high temperatures (70° C. to 80° C.) during the manufacturing process of such laundry articles enzymes cannot be present in the molten mixture of a detergent compositions since enzymes are sensitive to temperature. Another problem constitutes the high pH of the detergent compositions that is detrimental to enzyme stability.
It is an object of the present invention to provide a laundry article comprising a water-insoluble substrate coated with a detergent composition and an enzyme-containing composition.
Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description of the invention and the appended claims, taken in conjunction with the accompanying drawings and this background of the invention.